1. Field of the Invention
The present invention relates to a measurement data correction method applied in optical tomography for generating optical tomographic images with a measurement subject of a body tissue or the like, and to an optical tomography measurement device and a storage medium stored with a program.
2. Description of the Related Art
Body tissue has transmissivity to light of a specific wavelength, such as, for example, near infrared radiation. Therefore, in the field of pathology, for example, a fluorescent substance is administered to a living organism, fluorescent light generated from the administered fluorescent substance is measured two-dimensionally, and regenerated as a visible image (tomographic image) of, for example, the distribution state of the fluorescent substance in the body tissue.
Various image processing is performed in order to regenerate a correct image from measurement data. For example, in Japanese Patent Application Laid-Open (JP-A) No. 2004-125605 generation of image data at evenly spaced intervals by subjecting one-dimensional image data to interpolation, so as to regenerate a two-dimensional image, is proposed.
Further, in JP-A No. 2008-51773 regeneration of an image without density unevenness by storing shading data, and correcting image data obtained by measurement using the shading data, is proposed.
However, light of a specific wavelength, such as near infrared radiation or the like, propagates within a living organism while scattering isotropically. Therefore, in experimental fields such as pathology, using living organism such as small animals as the measurement subject, a fluorescent substance is joined to an antibody that specifically attaches to a lesion site, such as a tumor site or the like, and then administered to the measurement subject. Then, there is a proposal, in optical tomography using fluorescent light, to generate fluorescent light from the fluorescent substance by illuminating excitation light from the exterior of the measurement subject, receiving the light, and generating tomographic images in which the distribution of the fluorescent substance is regenerated (reconstructed) from the received fluorescent light.
By so doing, lesion sites within the measurement subject can be made clearly visible from the reconstructed optical tomographic images.
In fluorescent optical tomography, excitation light is illuminated towards a single point on the surface of a living organism, and fluorescent light generated from the fluorescent substance within the living organism by the excitation light and emitted externally is measured in plural locations in the same flat plane (measurement plane). In a case in which this is performed, while moving the illumination position of the excitation light around the periphery of the living organism, the position and density of the fluorescent substance is computed using measurement data obtained by measuring the fluorescent light at each of the respective illumination positions. By so doing, a two dimensional tomographic image is generated representing the density distribution of fluorescent substance (fluorescent light), sectioned on the measurement plane.
However, while illuminating excitation light towards the measurement subject and receiving the fluorescent light issuing from the measurement subject, not only is fluorescent light generated from the fluorescent substance received, but also various types of unwanted light, such as from reflected light of the excitation light and the like, are received, and data of this unwanted light is included within measurement data. This unwanted light prevents appropriate reconstruction of optical tomographic images.